Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f3efc2dd1090666…

MALICIOUS

PDF

71.0 KB Created: 2021-09-29 13:13:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3fb9f248108b9682012ad3686af2fac4 SHA-1: b1175d3d90b1c8ad87ed3ca33741ae8708bc2c17 SHA-256: 0f3efc2dd1090666a040b0e7d9ba5e42ecbf3b3664f95367f3df9f1585c3129f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs that point to various websites, including those hosted on compromised CMS uploads. This behavior suggests an attempt to lure users to malicious sites for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://inwebjor.ru/uplcv?utm_term=how+to+send+disappearing+messages+on+whatsapp+android
    • http://gibisch.org/files/files/70372219657.pdf
    • http://feynburg-uhren.de/uploads/43762570680.pdf
    • http://frankifoto.com/uploads/pages/files/gusutoregugamow.pdf
    • http://eqletstalk.com/uploads/files/202109240737142971.pdf
    • https://hippodrome-compiegne.fr/www/uploads/file/42461374479.pdf
    • https://realxenon.ru/uploads/files/84947612011.pdf
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/0a2e2eed4f6e0558d652d2b5aa20ec7d/fefapil.pdf
    • http://daegyung.kr/userfiles/file/20210906164818.pdf
    • https://die-elke.de/cms/elke_page_files/file/jakafolituxo.pdf
    • https://yensaovinastar.com/media/files/zojumunavazofijiwewisu.pdf
    • http://104450wp19.agentcentrum.com/userfiles/files/gokumemepe.pdf
    • https://windscrm.net/files/file/rilusirikutup.pdf
    • http://sacoorhealth.pt/site/upload/file/pivuvijasuf.pdf
    • https://ddmmaze.altruistictech.org/documents/img/upload/files/2637844205.pdf
    • http://www.enredmail.com/templates/files/idCliente_/file/52094116526.pdf
    • https://apartmani-mestrovic-krk.hr/files/jadudo.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/3028aea45945d064435f238944957338/zonegodifadij.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/d1e4dd71b25948f21bb4738d54bee9b2/82010526688.pdf
    • http://s4l.vn/storage/ckfinder/files/29037017731.pdf
    • https://cuichi177.com/uploads/files/202109121131399340.pdf
    • http://ganteltechnology.com/system/userfiles/file/meluwaxezemojez.pdf
    • https://homestayhoian.thamtuddt.com/uploads/image/files/xuwusumamixexevitifoziro.pdf
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/c7798c14b56ccd7275d69e6d76353ee4/vosewuri.pdf
    • https://vanchuyensahara.com/site/files/15649203676.pdf
    • http://progettocecinacuore.it/writable/public/userfiles/file/27848668965.pdf
    • http://kcntanduc.vn/img_duhoc/files/getiginusomujugirarafezaj.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2b3.bin
bdb71936145ce58938b803d838d28fe30dfed17f87d447d54cdf9e42f55c8970
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B3 10868 bytes
font_01_sfnt_off0000cb74.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB74 16792 bytes
font_02_sfnt_off0000e386.bin
4b879f13621e934db8d3993de1f09e3089eb4b308fd4d78c9dc34d270a84b3c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE386 16844 bytes